John henry holck



Patented Apr. 1!, I899..

J. H. HULCIL MEANS FOR DETACHABLY SECURING HUBS 0F CRANK ARMS UR LIKEPARTS T0 SHAFTS.

(Application filed Feb. 28, 1898.)

2 Sheets-Sheet II.

(No Model.)

i E 1E5 m Wk 6 F EB ,0,

No. 622,686. Patented Apr. :1, 1899.

.1. H. HOLCK.

MEANS FOR DETACHABLY SECURING HUBS 0F CRANK ARMS 0R LIKE PARTS TDSHAFTS. (Application filed Feb. 28, 1898.)

(No Model.) 2 Shegts$heet .2.

Imin" STATES ATnNr JOHN HENRY I-ICLCK, OF AURORA ILLINOIS, ASSIGNOR TOTHE AURORA AUTOMATIC MACHINERY COMPANY, OF SAME PLACE.

MEANS FOR DETAC HABLY SECURING HUBS OF CRANK-ARMS 0R LIKE PARTS TOSHAFTS.

SPECIFICATION forming part of Letters Patent No. 622,686, dated April11, 1899.

Application filed February 28, 1898. Serial No. 671,898. (No'modeL) Toto whom it may concern;

Be it known that 1, JOHN HENRY HoLoK, of Aurora, in the county of Kaneand State of Illinois, have invented certain new and useful Improvementsin Means for Detachably Securing the Hub of a Crank-Arm or Like Part toa Shaft; and I do hereby declare that the following is a full,.clear,and exact description thereof, reference being had to the accompanyingdrawings, and to the letters of reference marked thereon, which form apart of this specification.

This invention relates to an improved means for detachably securing thehub of a crankarm or like part to a shaft where it is desirable thatsuch arm be so constructed as to be easily removed and which at the sametime affords astrong and rigid connection between said parts whenconnected in their operative relation.

The invention is herein shown as applied to a crank-shaft for bicycles,whereby one arm may be detached and the shaft easily and quicklyseparated from its bearings; but it is to be understood that theinvention is not limited to such application.

The invention consists in the matters herein set forth, and moreparticularly pointed out in the appended claims.

In the drawings, Figure 1 is a view, partly in side elevation and partly.in section, of a crank-shaft embodying my invention. Fig. 2 is a viewof one end thereof. Fig. 3 is a section taken on line 8 3 of Fig. 1.Fig. 4 is a longitudinal side elevation of the lockingbolt removed. Fig.5 is a view, partly in longitudinal section and partly in elevation, ofanother form of crank-shaft provided with my invention. Fig. 6 is alongitudinal section of still another form of crank-shaft provided withmy invention. Fig. 7 is an end view of the same as seen from theright-hand side thereof.

Referring first to the construction shown in Figs. 1 to 1 of saiddrawings, A designates the crank-shaft, which in the present instance isprovided on one end with an integral crankarm B.

C designates a detachable crank-arm which is provided with an aperturedhub or enlarge ment which fits over a reduced portion CL of the shaft.

D designates a tube or sleeve adapted to fit closely about the shaft.Said sleeve is enlarged adjacent to its opposite ends to form the innerannular parts or cones D D of the bearing,the same being permanentlyattached thereto and preferably made of one piece or integral therewith.Said sleeve D is of a length to extend at its opposite ends into eontactwith the inner faces of the crank-arms B and C, so that the end faces ofthe sleeve form, in effect, shoulders on the shaft against which thecrank-hub rests and which determine the position of the said hub uponthe shaft.

To now refer to the parts more particularly concerned in my presentinvention, E designates a clamping-bolt which passes through an axialopening in the shaft and is provided on one end thereof with a head orshoulder which engages the removable arm C and is provided on itsopposite end with a screwthreaded nut which engages the outer .face ofthe opposite arms and by means of which the removable arm is clampedrigidly upon the shaft in contact with the shoulder formed by theadjacent end ofthe sleeve D. The construction by which locking action issecured is made as follows: The head of the bolt E consists, in theinstance illustrated, of a narrow block or T-head E which extends atright angles to the axis of the bolt and parallel with the arm C and isprovided with two locking studs or pins E E A recess or slot E is formedin the outer end of the shaft A to receive said head, which is ofgreater length than the diameter of the axle and extends at its outerends thereof into recesses 0, forming extensions of the recess E Thelockingpins E E constitute a means for preventing rotation of the armupon the shaft when said locking-bolt is in place and also to force orhold the hub of the crank-arm in contact with the shoulder on the shaft.Said locking-pins E are tapered and extend parallel with the axis of thelocking-bolt E and fit within oppositely arranged inwardly extendingtapered openings or sockets E the inner halves of which are formed inthe shaft and the outer halves of which are formed on the inner surfaceof the base of the hub which receives said shaft, said sockets beingdivided along lines which extend parallel with the axes thereof. Thepins and sockets are preferably circular in cross-sectional form. Saidsockets and the pins E fitting therein, bein g made of conical shape, itfollows that when said pins are drawn into the sockets by the action ofthe nut E upon the bolt the result ing wedge action will not only clampthe parts rigidly from relative rotation, but will tend to force andhold the hub in contact with the shoulder on the axle. The end portion aof the axle over which the arm fits is made of such length that thesleeve D extends beyond the same at the end adjacent to the arm 0, sothat when the arm 0 is placed on the axle it will rest in contact withthe outer end of the sleeve D. The recess E in the axle end is made ofsuch depth as to leave a space between the same and the inner face ofthe bolt-head E when the parts are assembled. Said space is provided notonly for movement of the pins into the wed ge-shaped holes within whichthey fit, but to provide for the movement necessary to take up all ofthe motion between the opposite ends of the sleeve B and the inner facesof the arms B and 0, whereby such parts maybe rigidly locked togetherwhen the nut is turned tightly upon the bolt. The tapering faces of thepins,which bear against the outer parts of the holes within which theyfit, or those parts formed in the arm 0, constitute bearing-surfaceswhich coact with the tapering bearing-surfaces formed in said arm by theconical construction of the holes to force the hub of the arm toward theadjacent end of the sleeve D;

With the construction described it will be seen that rotary movement ofthe arm 0 upon the shaftAis prevented both by the T-head E which fits inthe recess E in the end of the shaft and engages at its opposite endsthe oppositely-arranged recesses C in the arm 0, and by the pins E,which engage on the opposite sides thereof the oppositely-arrangedcircular longitudinal recesses in the shaft and arm and which form whenthe parts are assembled the sockets within which said pins fit.

The construction in which the pins E engage sockets formed partly in theshaft and partly in the arm is of much importance, as it greatlyincreases the strength of the connection between said parts, for thereason that the strain thereon is distributed throughout the length ofthe pins.

The construction described in which the locking-pins E and the recessesin which they fit are made of conical shape is of much practicalimportance, as it provides means for making an absolutely rigidconnection between the parts notwithstanding the slight inaccuracies inconstruction or variations in the size of the parts which necessarilyexist even with the most careful fitting of the parts, it being obviousthat if the pins and holes were made of uniform diameter throughouttheir length a slight looseness of fit between the pins and the engagingparts would permit lost motion between the arm and shaft. With thetapering construction described, on the other hand, it will only benecessary to draw the pins farther into the sockets, when the parts willbe forced into frictional engagement and the rigid connection betweenthe arm and shaft secured.

A further and important advantage gained by the use of the constructionherein described is the facility with which the crankarms may be removedfrom the shaft. In removing said arm the nut IE will be unscrewed and aslight tap upon the end of the bolt E will then unloosen the same fromits seat, so that the same may be easily withdrawn. The reduced portiona of the shaft being of circular form and of uniform diameter, said armmay be quickly and easily removed therefrom after said bolt has beenremoved.

A further advantage arising from the use of the construction describedisthat the shoulder which the hub of the crank-arm engages bears aconstant or uniform relation to the opposite end of the shaft or to asecond crankarm connected with said opposite end thereof, so that thedistance between such removable crank-arm and the opposite end of theshaft is absolutely fixed, the lost motion between the parts which isrequired for the tightening of the clamping-bolt being wholly outside ofsaid shoulder and therefore not affecting the relation between the armand the parts of the shaft inside of the same. Such a construction isespecially desirable in crankshafts for chainless wheels, in which it isabsolutely essential that the coacting gears be maintained in uniformrelation with respect to each other. This would obviously not be true ifthe connection between the arm and the shaft were such that the positionof the arm upon the shaft would not be accurately defined, as in thecase of a Wedge-shaped connection between the parts of a crank-arm andshaft, in which the final position of the arm upon the shaft could onlybe determined in each case by the particular shape of the parts andamount of clamping pressure brought to bear thereon.

The construction described affords a neat finish upon the outer face ofthe arm, the bolthead being made of convex form on its outer face, sothat whether or not its rests entirely within the slot E formed in theend of the axle, there will be no angular corners which would present anunattractive appearance. The crank-arm B, against which the nut E at theopposite end of the bolt rests, is provided with a conical recess,andthe inner face of the nut is provided with a correspondinglyshaped partwhich rests therein and which forms a frictional bearing between thesame to lessen the liability of the turning of the nut when it is inplace. Said nut will preffacing shoulders g.

erably be provided outside the face of the arm with angular faces ofsufficient depth to be engaged by a wrench or other tool.

It will be seen from the drawings that the locking-pins are located atsuch radial distance from the clamping-bolt as to permit the adjacentend of the shaft to extend between said pins and the bolt. With thisconstruction said lock ing-pins'exert a radial clamp ing action directlyupon the shaft and the part secured thereto,as well as a lateralclamping action. This is obviously of great importance, as it produces aconnection of great strength between said parts.

So far as the general features of my invention are concerned the meansfor clamping the arm from endwise movement on the shaft may be providedwith but one lockingpin or more than two of the same. A construction inwhich two pins are provided is preferred, however, as it gives suitablestrength in the joint and is cheaply and easily made.

In Fig. 5, F designates a tubular crankshaft, which is provided at oneend thereof with a reduced end portion f, forming with said end of theshaft an outwardly-facing shoulder f, against which the inner face ofthe arm C bears when slipped over said reduced portion of the shaft.Said shaft is provided adjacent to each end thereof with enlargementsforming cones F on the inner members of antifriction-bearings, saidcones being made an integral partof the shaft. The clamping-bolt E andthe parts connected therewith are of the same construction as thatdescribed in connection with Figs. lvto 4, inclusive, and operate in thesame manner as therein set forth.

My invention is shown in Figs. 6 and 7 as applied to a crank-shaft inwhich both of the arms are removably secured to the shaft. In saidconstruction, Gr designates a tubular shaft which is provided upon itsopposite ends with reduced end portions g, forming outwardly- Said shaftis provided adjacent its opposite ends with screw-threaded portions gupon which the inner members of the bearings, of any preferredconstruction, will be secured. H H designate crankarms which areconstructed to he slipped over the reduced end portions 9 of the shaftand which hear at their inner faces against the shoulders g. Idesignates a clampingbolt provided on one end with a T-head like thathereinbefore described, which is provided with inwardlyextendinglocking-pins 1 which fit in sockets I formed partly in the shaft andpartly in the arm, as in the previously-described constructions. Theconstruction of this end of the shaft and the parts connected therewithis the same as those hercinbefore described and need not be repeated. Atthe opposite end of the shaft said bolt is provided with ascrew-threaded portion upon which fits a nut 1 and between said nut andthe outer face of the adjacent arm is interposed a washer 1 which isprovided on its inner face with locking-pins 1 similar to thelocking-pins I on the opposite end of the bolt, which fit ininwardly-exteinda correspondingly-shaped projection which fits in saidrecess and which provides between the same a frictional hearing by meansof which said nut is retained in place. Vith this construction when thethe parts are assembled as shown in Fig. 6 and the nut I tightened uponthe bolt it will act to force the locking-pins I and 1 into theirrespective sockets, and thereby to force the crank-arms into rigidengagement with-the shoulder g and to lock said arms from rotarymovement upon the shaft.

The construction herein described is a desirable one for use inattaching a crank-arm of a bicycle to the shaft thereof, as it securelylocks the arm upon the shaft without lessening the distance between thearms while being tightened. Furthermore, with this constructionunsightly projections at the ends of the axles are avoided, as theclamping-nut is so arranged as to be entirely out of the way and takesup no extra room, while the head at the opposite end of the axle is suchas to provide a neat finish betweenthe same and the adjacent arm.

While the invention has been described in connection with crank-shaftsand is herein shown in connection with bicycle crank-sh afts, it isevident that it need not be restricted to such application. Theinvention may obviously be used with equal advantage for removablyfastening a gear or pulley to the end of a shaft, in which event theoperative parts of the invention would be made in all respects similarto those herein shown.

I claim as my invention 1. The combination with a tubular crankshaft andthe hub of a crank-arm or the like constructed to be slipped over oneend of said shaft, of means for detachably connecting the arm with theshaft comprising a clamping-bolt, a T-head on one end of said bolt,tapered locking-pins upon said head, said pins being adapted to engagetapered sockets formed partly in the shaft and partly in the arm andbeing located at such radial distance from said bolt as to permit aportion of the shaft to pass between the same and the said bolt.

2. The combination with a tubular crankshaft and the hub of a crank-armor the like constructed to be slipped over one end of said shaft, saidshaft being provided in its end with a transverse recess, of aclamping-bolt, a T-head on the end of said bolt engaging said recess anda tapered locking-pin attached to said T-head and adapted to engage atapered socket formed partly in the shaft and partly in the arm.

3. The combination with a tubular crankshaft and the hub of an arm orthe like constructed to be slipped over one end of said shaft, saidshaft being provided in its end with a transverse recess, of means fordetachably connecting the hub with the shaft comprising a clamping-bolt,a T-head on said bolt engaging the slot or recess in the end of theshaft and engaging at its opposite ends recesses in said hub and alocking-pin connected with said T-head and fitting with a socket formedpartly in the shaft and partly in the arm. a

4. The combination of a tubular crankshaft having on one end an arm, asleeve of less length than said shaft, surrounding said shaft whichengages at one end said arm and forms at the other end of the shaft ashoulder, a removable arm fitting over said other end of the shaft andengaging said shoulder, and a bolt passing through said tubular shaftand provided on one end with a clamping-nut and on its other end With atapered locking pin fitting into a socket formed partly in said shaftand partly in said arm.

5. The combination of a tubular crankshaft having on one end an arm, asleeve surrounding said shaft of less length than the shaft whichengages at one end said arm and forms at the other end of the shaft ashoulder, a removable arm 'fitting over said other end of the shaft andengaging said shoulder, said shaft being provided in its free end with atransverse recess, a bolt passing through said tubular shaft andprovided on one end by a clamping-nut, a T-head on the opposite end ofsaid bolt engaging said recess in the end of the shaft, and a taperedlocking-pin connected with said T-head and fitting into a socket formedpartly in the shaft and partly in the arm. 7

In testimony that I claim the foregoing as my invention I aflix mysignature, in presence of two Witnesses, this 26th day of January, A. D.1898.

JOHN HENRY HOLCK.

\Vitnesses:

AXEL LEVEDALX, BERT KING.

